Question

A transistor is used as a common emitter amplifier with a load resistance $2Kohm$. The input resistance is $150Ohm$. Base current is charged by $20\mu A$ which results in a change in collector current by $1.5mA$. The voltage gain of the amplifier is

• A. $900$
• B. $1000$
• C. $1100$
• D. $1200$

Answer 1

Answer: (B)

$1000$

We know that voltage gain, $\frac{V_o}{V_i}=\beta \frac{R_L}{R_I}$

Where, $\beta =\frac{I_C}{I_B}=\frac{1.5mA}{20\mu A}=75$

Hence, voltage gain=$75\times \frac{2000}{150}=1000$

Hence, answer is option-(B).